George a



(No Model.)

G. A. BOYDEN.

PRESSURE REGULATING VALVE.

No. 405,981. Patented June 25, 1889.

ZZI'T'NEEEEE':

I UNITED STATES PATENT OFFICE.

GEORGE A. BOYDEN, OF BALTIMORE, MARYLAND, ASSIGNOR TO THE BOYDEN PO\VER BRAKE COMPANY, OF SAME PLACE.

PRESSURE-REGULATING VALVE SPECIFICATION forming part of Letters Patent No. 405,981, dated June 25, 1889.

Application filed January 7, 1889. Serial No. 295,626. (No model.)

To all whom it may concern:

Be it known that I, GEORGE A. BOYDEN, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Pressure-Regulating Valves; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon,which form a part of this specification.

In the construction and operation of airbrakes on railroad-trains it is very necessary that provision be made for storing in the airtank on the locomotive a volume of air at a snfficiently high pressure to at all times insure the needed power for the quick operation of the brakes.

To this end my invention relates and consists of a pressure-regulating valve of certain construction, which is placed in the air-pipe, whereby any pressure of air may be maintained in the air-tank, and only such pressure admitted to the train-pipe as will be required to operate the brake mechanism, thereby maintaining in the air-tank an excess of volume and pressure of air to at all times insure SUflIOlGIll; power to operate the brakes, all of which I accomplish by the devices hereinafter fully described and claimed, reference being had to the accompanying drawings, in which Figure I is a side elevation in full of the regulating-valve. Fig. II is a sectional view of the device as shown in Fig. I.

The same figures refer to the same or similar parts throughout the several views.

The figure 3 denotes the casing of the device, which consists of an upper chamber 4 and lower chamber 5, of different diameters, the upper chamber having the grcatest diameter, these two chambers being connect ed by the ligament 0, through which is extended the port 7, whereby communcation is established, respectively, between the outer ends of the said upper and lower chambers. Fitting air-tight in the upper chamber, which is of cylindrical form, is the piston 8, that is made air-tight by the packing-rings 9, the pressure from the air tank being admitted to the upper surface of this piston 8 through the port 7 in a manner that will be presently described, and serving to force the said piston downward, the upward movement being imparted thereto by means of the spring 10, that is placed on the under side thereof, and is backed by the adjustable nut 11, which is threaded in the bottom of this upper chamber, whereby it may be screwed in or out, and thus put more or less tension upon the spring 10. To form a stop to the upward movement of the piston 8, the cap 12, which is screwed in the upper end of the casing 3, is provided with the points 13 thereon, against which the upper surface of the said piston 8 strikes, this cap 12 having the opening 14, through which the air passes to the engineers brakevalve and train-pipe after ithas gone through the regulating'valve, the end of this cap 12 being threaded, whereby the proper connec tion is made to the air-pipe.

The bottom of the lower chamber 5 is made open and has screwed therein the cap 15, which is connected directly to the air storage tank, through which the air is admitted to the regulating valve through the opening 16 therein, whence it passes through the port 7 and reaches the upper surface of the piston 8. In order to control the volume and pressure of air which will be permitted to pass through this opening 10 from the air-storage tank, the piston-rod 17 of the piston Sis extended downward into the lower chamber 5, and has secured on the end thereof the valve 18, which is faced with rubber 19, or some suitable elastic material, which in the downward.

movement of the piston 8 will be brought in contact with the valve-seat 20, that is formed in the lower'cap 15, and thus close the communication with the air-storage tank through this opening, a packing-box 21 being provided in the upper end of thelower chamber around the piston-rod 17 to prevent the leakage of air at this point.

The manner of operating is as follows: As stated, "the upper end of the regulating-valve is connected directly to the engineers brakevalve, and the lower end thereof is connected directly to the air-storagetank. As shown in Fig. 11, the valve 18 is off its seat 20 and the air-pressure willbe permitted to pass through A the opening 16, the port 7, and the opening 14 to the engineers valve, the pressure acting upon the upper surface of the piston 8, and in consequence of the greater area thereof will tend to force the said piston downward, moving in unison therewith the valve 18, which will be brought more or less near its seat 20, thereby restricting or wholly shutting off the supply of air from the air-storage tank through this opening 16 until the pressure on the upper side of the said piston 8 shall have become sufficiently lessened to permit this valve 1.8 to be raised from its seat by the tension of the spring acting on the under side of the said piston,and thus again establish communication between the air-storage tank and the engineers brake-valve, the adjustable nut 11, by being screwed in or out of the chamber, serving to put that tension upon the spring 10 that just that resistance will be offered to the downward movement of the piston 8 as will permit only such quantity of air to pass through the opening 16 from the airstorage tank as is required to operate the brakes.

Having described myinvention and the man ner of operating it, What I claim, and desire to secure by United States Letters Patent, is-

l. A pressure-regulating valve having a casing with two chambers, the chambers having a communicating passage within the casing, a piston in one of said chambers having one end of its rod passinginto the other chamber, a valve secured to theend of said rod and having a seat on the wall of the opening of an inlet-pipe to said last-mentioned chamber, a hollow cap with points on the end of the easing, and a spring in the piston-chamber, substantially as and for the purpose set forth.

2. In apressure-regulatin g valve, the casing 3, having the chambers 4 and 5 and the communicating passage 7, the piston 8 in said chamber 4, having its stem projecting into chamber 5, the (valve 18 on the end of said piston-rod, the cap 15, secured in one of the chambers and forming a seat for the valve 18, the spring 10, bearing against the piston 8, the nut 11, secured to said spring, and the abutting cap 12, the said parts being combined and arranged to operate substantially as specified.

3. In a pressure-regulating valve having a chamber with a piston therein, a hollow cap secured to the wall of the chamber and having inwardly-projecting points, and an inletpassage communicating with the hollow cap above the piston, the said points of the cap adapted to limit the play of the piston, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE A. BOYDEN.

\Vitnesses:

B. FRANK. BOYDEN, J NO. T. MADDOX. 

